Walkers has started using British-sourced ingredients to flavour its core range of crisps.

Among the flavourings to be introduced by brand owner PepsiCo are Cheddar from Somerset, tomatoes from the Vale of Evesham and sour cream from Dorset. The company was already using salt from Cheshire and will now also be using British vinegar.

Walkers, which has been using only British potatoes since 2007, said it hadn’t been possible to source all flavourings from the UK. “We are continually reviewing our suppliers, but at present onions, for example, are sourced from the US as we haven’t managed to perfect the taste of cheese & onion using a different home-grown source,” said a spokesman.

The announcement comes a week after poor harvests forced Premier Foods to renege on its pledge to source all wheat for its Hovis brand from the UK.

Walkers said its was committed to using British ingredients. “We can’t speculate on the impact of future harvests but our primary commitment will always be to offer our customers the best taste and quality,” it added.

The brand has also revamped its packaging, which will feature a Union Jack potato image, an updated logo and richer colours. The names of flavours will now also flag up the British sourcing of the ingredients.

The move will be supported from March by a campaign including TV ads featuring Gary Lineker and tractor-shaped display units in stores and depots.